Can supernovae quench star formation in high-$z$ galaxies?

Abstract

JWST is providing the unique opportunity to directly study feedback processes regulating star formation (SF) in early galaxies. The two $z>5$ quiescent systems (JADES-GS-z7-01-QU and MACS0417-z5BBG) detected so far show a recent starburst after which SF is suppressed. To clarify whether such quenching is due to supernova (SN) feedback, we have developed a minimal physical model. We derive a condition on the minimum star formation rate, $\mathrm{SF}{\mathrm{R}}_{\min }$, lasting for a time interval $\Delta t_b$, required to quench SF in a galaxy at redshift $z$, with gas metallicity $Z$, and hosted by a halo of mass $M_h$. We find that lower $(z,Z,M_h)$ systems are more easily quenched. We then apply the condition to JADES-GS-z7-01-QU ($z=7.3$, $M_{\star }=10^{8.6}{M}_{\odot }$) and MACS0417-z5BBG ($z=5.2$, $M_{\star }=10^{7.6}{M}_{\odot }$), and find that SN feedback largely fails to reproduce the observed quenched SF history. Alternatively, we suggest that SF is rapidly suppressed by radiation-driven dusty outflows sustained by the high specific SFR (43 and 25 Gyr${}^{-1}$, respectively) of the two galaxies. Our model provides a simple tool to interpret the SF histories of post-starburst galaxies, and unravel quenching mechanisms from incoming JWST data.

8 pages, 5 figures, sumbitted to ApJ